Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered by structured data. The description contributes real context beyond that: the source domain, that entries are dated and sourced, and that results come newest first. It says nothing about rate limits, pagination, or what an empty result means.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three sentences, front-loaded with source and content scope, then ordering ("Newest first"), then the usage trigger. The enumeration is long but every item earns its place by mapping to a filterable category.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With four optional params, no output schema, and safety covered by annotations, the description supplies what is missing: where the data comes from, what kinds of entries exist, and what order they arrive in. It stops short of describing result shape or behavior at the 84-day/50-item bounds, but nothing essential to invoking it is absent.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 75%, below the high-coverage baseline, so the description must add value – and it does, effectively enumerating the change kinds (price, trial, feature, integration, rating, platform) that the `kind` parameter accepts even though the schema declares no enums. The `tool_id` pointer to search_tools is in the schema, not the description, and `limit` is undocumented in both, so it does not fully compensate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description names a specific resource and source ("Dated, sourced changes from aitools.obzdn.co/changes/") and enumerates the exact change categories covered: price/plan changes, trials, features, integrations, rating changes, and platform-owner changes. That scope is clearly distinct from search_tools or get_tool, which retrieve tool records rather than a chronological change feed.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives explicit trigger conditions: "Use it before recommending a tool, or when someone asks what changed." This tells the agent when to reach for it, but it does not name the alternative siblings (search_tools, get_tool) or state when this tool is the wrong choice.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.